1. Field of the Invention
This invention relates to a sheet processing apparatus and a processing method to take out plural sheets on a transport path one by one detect, classify and stack based on the detection result.
2. Description of the Related Art
A sheet processing apparatus that feeds plural sheets one by one on a transport path, detects them, judges classifications, and based on this judging results, classifies and stacks sheets is so far known as disclosed in Japanese Patent Publication No. 2001-93026.
On a transport path, there are provided plural sensors, the conveying state and conveying a CPU monitors positions of all sheets taken out on a transport path.
When sheets being conveyed are jammed in this apparatus, the operations of the entire apparatus are once operator removes suspended and jammed sheets from the processor.
Two sensors provided on a transport path detect the jamming of sheets. That is, the number of sheets passed each of the sensors are counted by a CPU and if there is a difference between the number of sheets counted by a sensor provided at the upper stream side along the transport path and the number of sheets counted by a sensor provided at the downstream side, the CPU judges that there is the jamming of sheets between two sensors.
Then, when the jam releasing process and the initializing process are executed by operator after removing jammed sheets, the number of sheets passed the sensor at the downstream side is decided and the sheets are conveyed to a specified destination.
However, when the sheet processing apparatus is suspended to operate simultaneously with the jamming as described above for the slip between a conveyor belt and sheets and inertia of the sheets, there is the possibility for generating new defects such as, for example, conveying gap, shifts and the like even for sheets that are not jammed and to be properly conveyed. When such defects are caused, sheets that should have been conveyed normally by passing through the downstream side sensor may not be normally processed.
Further, when such the uncertain process is decided to be the normal process, serious problems such as erroneous counting, etc. may result.